(a) Field of the Invention
The present invention relates to a thin film transistor array panel, and a manufacturing method thereof.
(b) Description of the Related Art
Liquid crystal displays (LCDs) are one of the most widely used flat panel displays. An LCD includes two panels provided with field-generating electrodes and a liquid crystal (LC) layer interposed therebetween. The LCD displays images by applying voltages to the field-generating electrodes to generate an electric field in the LC layer, which determines orientations of LC molecules in the LC layer to adjust polarization of incident light.
In LCDs that include field-generating electrodes on respective panels, a plurality of pixel electrodes arranged in a matrix are provided on one panel and a common electrode is provided covering an entire surface of the other panel. Image display of the LCD is accomplished by applying individual voltages to the respective pixel electrodes. For the application of the individual voltages, a plurality of three-terminal thin film transistors (TFTs) are connected to the respective pixel electrodes, and a plurality of gate lines transmitting signals for controlling the TFTs and a plurality of data lines transmitting voltages to be applied to the pixel electrodes are provided on the panel. Also, a plurality of storage electrodes overlapping the pixel electrodes to form a storage capacitor are provided on the panel.
Several photolithography steps are usually required for manufacturing the LCD panel. Since the production cost increases as the number of photolithography steps increases, it is preferable to reduce the number of photolithography steps. To reduce the production cost, the data lines and a semiconductor layer are patterned using one photoresist, including a portion having a middle thickness, as an etch mask.
However, because the semiconductor layer remains under a conductor connected to the pixel electrodes and overlaps the storage electrodes in this manufacturing method, a flicker on the screen as well as an afterimage are generated, thereby deteriorating the characteristics of the LCD.